Delay in retinal photoreceptor development in very preterm compared to term infants

Area of Science:

• Ophthalmology
• Neonatology
• Developmental Biology

Background:

• Preterm birth (<32 weeks gestational age) can affect visual development.
• Photoreceptor maturation is crucial for visual acuity.
• Spectral domain optical coherence tomography (SD-OCT) allows non-invasive imaging of retinal microanatomy.

Purpose of the Study:

• To compare photoreceptor development in very preterm (VPT) infants versus term infants using SD-OCT.
• To assess retinal layer maturity in VPT infants at term equivalent age (TEA).

Main Methods:

• SD-OCT imaging of the macula was performed at the bedside in VPT and term infants.
• Qualitative and quantitative analyses focused on retinal and photoreceptor layers.
• Measures included ellipsoid zone (EZ) presence, EZ to Bruch's membrane (BM) distance, and radial EZ appearance distance.

Main Results:

• The incidence of a developed EZ at the foveal center was significantly lower in VPT infants (14%) compared to term infants (47%).
• VPT infants had a greater mean distance from the foveal center to the visible EZ (783 μm) versus term infants (492 μm).
• No significant difference was found in BM-to-EZ height; the cone outer segment tips (COST) band was not visible in any infant.

Conclusions:

• Photoreceptor development, including inner and outer segments, is delayed in VPT infants at TEA.
• The photoreceptor RPE junction remains immature in all infants studied at TEA.
• Delayed photoreceptor maturation may contribute to visual function deficits in VPT infants.